A method by which containers are sterilized in an inverted state by using a sterilizing liquid such as an aqueous solution of peracetic acid has been widely used for sterilizing bottle containers in an aseptic loading system. The sterilization effect of the inside of the container in this method due to wetting of the inner surface of the container by the sprayed sterilizing liquid, and in order to obtain good sterilization effect, the entire inner surface of the container has to be wetted uniformly with the sterilizing liquid. Furthermore, in the washing process performed after the sterilization process, the sterilizing liquid that has adhered to the entire inner surface of the container has to be washed down without leak. With the conventional method for washing inverted containers, a washing nozzle is inserted into the mouth of the container and a washing fluid (mainly, aseptic water) is sprayed therefrom. If the sprayed amount of the washing fluid is small, the ability to wet uniformly the entire inner surface of the bottle is lost and washing leak appears on the inner surface of the container. For this reason, a large quantity of the washing fluid has to be sprayed inside of the container. In particular, in the case of synthetic resin containers such as PET bottles, peaks and valleys of complex shape, such as reinforcing ribs, are present on the bottom and body section to increase the rigidity of container. Therefore, a large quantity of washing fluid has to be sprayed over a long period in order to wet uniformly the entire inner surface of the container, thereby hindering the transition to high-speed lines that has been urgently required in recent years. Furthermore, since a large quantity of washing fluid is required, it causes waste of the washing fluid and cost increase. In order to solve the above-described problems, the inventors have suggested a method and a fluid spraying nozzle by which the contact ratio of a washing fluid with the inner surface of a bottle is increased and washing is conducted with high efficiency in which a first spraying hole is formed in the center of a distal end section of a spraying nozzle that is to be inserted into the mouth of the inverted bottle and a second spraying hole is formed to be opened below the first spraying hole, the washing liquid sprayed from the two spraying holes toward the bottom section of the container flows down, and part of the liquid is stirred and pushed up by the washing fluid sprayed from the second spraying hole and scattered over the inner surface of the bottle (ref. Patent Document 1).
A method and nozzle for washing and sterilizing containers according to which a nozzle having a liquid receiving section is disposed below a container mouth and a liquid flow from a liquid ejection hole is caused to pass through a reflux flow that was retained in the liquid-receiving section, whereby the ejected liquid is caused to oscillate and the distal end of the liquid flow that collides with the inner surface of the container is constantly oscillated over the inner surface of the bottom section of the container, thereby increasing the contact ratio with the flow with the inner surface of the container, has also been suggested as a method for sterilizing or washing a container in which the container is held in an inverted state and a nozzle is not inserted into the container (ref. Patent Document 2).    Patent Document 1:    Japanese Patent Application Laid-open No. 2003-181404    Patent Document 2:    Japanese Patent Application Laid-open No. H6-121974